1. Field of the Invention
The present invention relates to lighting for use in transportation and industrial equipment used in mining, construction, automotive, investigations, land surveying, emergency services in low light conditions.
2. Description of the Related Art
Traditionally low light conditions have presented a hazard to construction workers and the like, thus personal protective equipment is often used to promote visibility. The introduction of LED lighting technology has reduced much of the ultraviolet (UV) radiation emitted from an artificial source to near zero. While the efficiency of the LED lighting is very desirable, its use alters the spectral breadth of the light being produced. The lack of ultraviolet light degrades the effectiveness of safety markings placed on equipment and the clothing and safety equipment worn by personnel, in that many of such markings are designed to fluoresce, which requires the presence of UV spectral power.
Ultraviolet light is an electromagnetic radiation with a wavelength from roughly 10 nm (30 PHz) to 380 nm (750 THz), which is a shorter wavelength than that of visible light but longer than X-rays. UV radiation is present in sunlight, and also produced by electric arcs and specialized lights such as mercury-vapor lamps, tanning lamps, and black lights. Although the UV light lacks the energy to ionize atoms, long-wavelength ultraviolet radiation can influence chemical reactions, and causes many substances to glow or fluoresce.
In U.S. Pat. No. 6,122,093 there is disclosed a reduced ultraviolet radiation transmitting, safety protected electrochromic glazing assembly. The electrochromic glazing assembly has reduced UV radiation transmission and safety protection. The assembly may include at least a pair of glass or other elements confining an electrochromic medium therebetween. Ultraviolet radiation reducing means are incorporated for reducing ultraviolet radiation transmission through the assembly. A polymeric antilacerative layer is disposed on one surface of one of the glass elements for preventing lacerative injuries (Abstract). There is much prior art directed at the reducing of UV transmission, which is part of the problem that is addressed by the present invention.
What is needed in the art is a means of providing the needed ultraviolet radiation in conjunction with light of the visible light spectrum, to improve the fluorescing of reflectors in low light conditions.